A preliminary study on the development of La2O3-bearing nanostructured ferritic steels via high energy ball milling

Elemental powder mixture of Fe–Cr–Ti–Mo and La2O3 were ball milled for different milling times in a high energy shaker mill. Effects of ball milling time on crystallite size, particle size and hardness were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and microhardness tester. After 10 h of ball milling, the smallest crystallite size and highest hardness were ∼24 nm and ∼970 HV, respectively. Transmission electron microscopy (TEM) studies have revealed nanoscale features 2–5 nm in diameter present in the milled powder. Local atom probe tomography studies have shown that these nanoscale features were possibly nanoclusters enriched in La, TiO and O.